Cardiogenic shock is a clinical state with an eighty per cent mortality characterized by a failure of the circulation to provide adequate tissue perfusion. Treatment should be directed toward an improvement of effective blood flow and the relevant question is to find the ideal agent or combination of agents which will correct the maldistribution of blood flow. Most previous studies of cardiogenic shock have paid little attention to the diversion of blood flow from one vascular bed to another. It is not sufficient to examine only the heart when studying cardiogenic shock, yetthis is where mot investigations have been focused. Also, most of these studies have been carried out in the canine subjected to various surgical and anesthetic procedures which undoubtedly modify their response to shock and therapy. The object of this research is to develop a standardized primate model for the study of cardiogenic shock, free of the complications surgery and anesthesia. This will be accomplished by embolizing the coronary circulation with plastic microspheres via a previously inserted double-lumen balloon catheter with the tip located at the base of the aorta. After the established criteria for cardiogenic shock have been met, the alterations in total and regional blood flow as well as the distribution of the cardiac output will be determined by the radioactive microspheres technique. This method consists of injecting nonrecirculating carbonized microspheres, labeled with different gamma- emitting radioactive nuclides, into the left ventricle of the heart. The microsopheres are mixed with the blood in the left ventricle and are distributed to each organ and tissue in direct proportion to its blood flow through trapping in tissue arterioles. Later the animal is dissected and the radioactivity in all organs and tissues is measured. The influence of various vasoconstrictors, vasodilators, inotropic agents, glucocortiscosteroids and celiac plexus block on these same parameters during control and experimental shock conditions will be studied.